2.1. Patients
Mycobacteria assay: In a first step, we identified two patients recently diagnosed at the Institute of Pathology, University of Bern. The first was a 21 year-old male with a histological diagnosis of granulomatous lymphadenitis compatible with tuberculosis. A molecular test for mycobacterium tuberculosis, bovis and BCG was made and confirmed the presence of the bacteria. The second was a 67 year-old woman with right-sided colon cancer and no evidence of mycobacterial infection. Formalin-fixed paraffin-embedded tissue blocks from the lymph nodes and cancer, respectively, were retrieved from the tissue archive.
KRAS assay: In a second step, we identified six patients also recently diagnosed with metastasizing colorectal cancer diagnosed at the same Institute. All underwent mutation analysis for KRAS Exon 2, codons 12 and 13 using pyrosequencing. Three patients were wild-type (WT); one patient had a colorectal cancer with G12D mutation, the second a G12V mutation and the third was mutated in codon 13 (G13D).